PORTLAND, Ore.  The trial of a man accused of attempting to detonate an 1,800-pound bomb at a Portland Christmas tree-lighting ceremony begins this week.

Mohamed Mohamud is accused of attempting to detonate a weapon of mass destruction in November 2010. The bomb was a fake provided by law enforcement.

His defense said they will argue Mohamud was entrapped by the FBI. The 21-year-old Mohamud is one of the youngest defendants ensnared by the Justice Department’s terror stings. The operations and the FBI’s informant network were ramped up after Sept. 11, 2001 terrorist attacks.

Mohamud’s attorneys said his youth made him a vulnerable target.

Prosecutors argue that Mohamud was predisposed to committing terrorism before the operation began. They said Mohamud was offered the option of peaceful resistance, but chose a path of violence.